I was wondering if thread actually gets "old" and shouldn't be used. I have some thread that I have had for years and would like to use up but am afraid it might get weak with age and shouldn't be used. I am talking more about regular sewing thread, but I guess my question would pertain to serger cones, quilting thread, etc.

Do the tug test. Old thread can get brittle (particularly if it was exposed to sunlight) and if it is brittle, it will tear easily when you tug firmly. If it takes real effort to tear the thread off the spool, then it should be OK to use.

It can get old. It depends on the conditions of storage. It can dry rot.

Karen, the answer to your questions is Yes! Thread ages just like everything else. It doesn't matter if it's synthetic or all cotton. The best place to store any thread is out of direct sunlight and in a low humidity area. What's the sense of putting hours into the fabrication of a quilt if the tensile strength of the thread has been compromised due to old age?

Happy Scissoring,
Michael

Hey Michael, I do not age! I am timeless. (okay, warped in a few spots, but not delapidated. ;) )

give it a good tug- compare it to the strength of a newer thread- i've been helping my mother use up a supply of cones that we've been using since 1994- i really don't know how long she had it before i started helping use it...it is still good strong thread.
and in the quilt museums there are quilts from the 1700's the thread is still holding them together.

Great question and so timely for me. My mom just gave me a huge bag of thread. There were probably 150 spools or more. I shared them with my darling daughter who is just beginning to sew. We are both thrilled to have such a great stash of thread! We will be giving it the 'tug' test before stitching away on projects.

I use all my thread no matter how old it is. I have had new thread (less than a couple of years old) that breaks while I'm using it. No sun on thread here.

Polyester or cotton wrapped poly is much less likely to age than all cotton. You know all the polyester pants we wore in the 70s are going to be in the landfills 100 years from now, still shining brightly and as strong as ever. I would test it, but expect breakage at a certain point in anything except the invisible stuff that looks like fishing line.

they can get old, they can get dry rot, they can mold...you just do the tug test..if it seems to break easily then spritz with water and place in a ziploc or covered plastic dish in the fridge for a few days to rehydrate the thread. Of course this only works on 100% or silk..not on blends..if a blend breaks easily toss it out or keep it for sewing on buttons!